retired

My 2004 Cherokee heater fan suddenly stopped running while in operation. Removed fan motor, and hot wired it to battery quickly and it ran. Prior to loosing fan motor, lost blender doors, replaced doors with single operation door. Then it seems the actulator has gone bad, so while I'm getting a new actulator I blocked doors in heating mode. Now the motor completely stopped running. I also did a code check and have the following codes coming up -- 22, 52, 54, & 56. Dose anyone have any suggestions of what I can check next?

maddogs1965

Not sure if your 2004 is the same as a my 2000 but under the dash to the left of your blower motor there is a electronic resistor (black box) that is basically a printed circuit board. They are know for getting VERY hot when you have the fan on a low speed since they are dropping the voltage to you fan motor. I have had to replace mine and on my friends 1999 G.C.

Another problem they have, once you remove the box, look at the wires that power it from the wiring harness, the ground wire gets so hot that it melts the wire and connection. Both of the resistors i have replaced, i have had to cut the wires and put my own new female connections back on so there was a good connection again, or the ground wire would loose connection, and every bump in the road, the blower motor would quit working.

Before you remove the resistor, wiggle the wires that actually feed power to the resistor box, and see if the fan starts working again, if it does, then you also have a bad connection like i did, if the fan does not come on at all i would say the resistor took a dump and you need a new one.

Code 22 left temperature door travel range travel too large ( this would relate back to you blocking the door off or the actuator motor being broke)

Code 52 re-circulation door travel to far

Code 54 Left temperature door travel to large

Code 56 Right temperature door travel to large

dave1123

IDK if this makes a difference or not, but the dual zone heater has 2 stepper-motors the operate the blend doors. One is behind the heater box and one is in front. If you replaced the 2 doors with a single door, the rear motor may be jamming the front motor, causing you to get these weird codes.